Snapshot reveals a black hole’s jets

A network of radio telescopes scattered around the Southern Hemisphere has produced the best-ever view of cosmic jets erupting from a supermassive black hole at the center of another galaxy.

The new image shows a region of space less than 4.2 light-years across at the heart of Centaurus A, 12 million light-years away in the constellation Centaurus (of course). The galaxy, also known as NGC 5128 is anchored by a black hole as massive as 55 million suns. It’s a huge radio source. In fact, if our eyes could see radio waves, Centaurus A would look nearly times wider than the full moon, due to the giant lobes of radio-emitting matter spreading out from the galaxy itself.

The matter is streaming into the lobes via the particle jets that emanate from the black hole.

“These jets arise as infalling matter approaches the black hole, but we don’t yet know the details of how they form and maintain themselves,” Cornelia Müller, a doctoral student at the University of Erlangen-Nuremberg in Germany, said in a NASA image advisory released today.

Müller is the lead author of a study about the jets, appearing in the June issue of Astronomy and Astrophysics. She and her colleagues targeted Centaurus A with a network of nine radio telescopes in Africa, South America and Australia, known collectively as the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry project, or TANAMI. The telescopes joined forces to zoom in on the heart of the galaxy.

Left: The giant elliptical galaxy NGC 5128 is the radio source known as Centaurus A. Vast radio-emitting lobes (shown as orange in this optical/radio composite) extend nearly a million light-years from the galaxy. Right: The radio image from the TANAMI project provides the sharpest-ever view of a supermassive black hole’s jets. This view reveals the inner 4.16 light-years of the jet and counterjet, a span less than the distance between our sun and the nearest star. Undetected between the jets is the galaxy’s 55-million-solar-mass black hole.

“Advanced computer techniques allow us to combine data from the individual telescopes to yield images with the sharpness of a single giant telescope, one nearly as large as Earth itself,” Roopesh Ojha of NASA’s Goddard Space Flight Center explained.

The radio image shows features as small as 15 light-days across, which makes it the highest-resolution view of galactic jets ever made. Studying the jets in such detail should help astronomers figure out how they form — which would make Müller very happy.